Mr David Davis became the third candidate to launch his bid for the Conservative leadership yesterday pledging to build a modern party and win back a "lost generation" of voters.
The former minister for Europe and Eurosceptic acknowledged he was the "dark horse" candidate and he made it clear that after two crushing general election defeats the party had to make a clean break from the past.
"I want to build a modern Conservative Party, true to our principles but willing to think again about the issues that matter most to people," he said, indicating he would allow shadow cabinet members to step down to campaign for the euro.
"We must be true to Conservative principles of choice, individual responsibility and freedom. But that does not release us from the painful necessity for thought about making ourselves relevant. We cannot hide from the 21st century and the real world in which we live."
As he had indicated on Monday, the Eurosceptic shadow defence secretary, Mr Iain Duncan-Smith, also formally launched his leadership bid. He also insisted members of his shadow cabinet who could not campaign in favour of keeping the pound in a referendum on membership of the single currency, would be allowed to temporarily step down.
"Labour want to scrap the pound and join the euro. To do so they must hold a referendum. My views about Europe are well known and will not change. However, I recognise that there is a minority in the Conservative Party who take a different view. I want front benchers to be able to serve on the understanding that as and when the referendum comes those who disagree with the party line can temporarily stand down and campaign for the euro."
He wanted to "close the book" on Conservative divisions over Europe.